Peptide growth factors and their receptors have both been implicated as potential mediators of some of the physiologic effects of sex steroid hormones on human endometrium. Preliminary work carried out by ourselves and others suggest 1) that CSF-1 (colony stimulating factor) and its receptor are present in normal and neoplastic endometrium and 2) that expression of both genes may be under the control of steroid hormones. In this application we propose to extend our ongoing investigations on the physiology of CSF-1 and its receptor in ovarian and endometrial carcinomas funded by R29-CA47292 to normal endometrium, particularly to investigate the physiologic and molecular biological relationships involving this growth factor, its receptor, and sex and glucocorticoid steroid hormones.